1. Field of the Invention
The present invention pertains to the field of clutching mechanisms, and, in particular, to a rolling-element clutch.
2. Description of the Related Art
A freewheel clutch is a device that will drive a rotating load in one direction, but will allow it to freewheel or spin at any speed in the other direction. There is a need to make a more compact and rugged freewheel clutch. All current designs need separate devices to support the rotating load on the shaft and to have the shaft drive this load. Current techniques are called ratchet and pawl, wrap spring, sprag, roller clutch, ball clutch, tilting plate, and so forth. Each of these related art devices needs the addition of some bearing device to support the driven load when it is in the freewheel mode.
The typical related art is represented by a one-way clutch bearing having an outer race with an annular inner surface, an inner race with an annular outer surface corresponding to and concentric with the inner surface, and rolling members disposed in an annular space formed between the inner surface and the outer surface, whereby relative rotation of the inner and outer races in one direction is prevented by displacement of the rolling members in the space and a torque is transmitted. A holding means for holding the rolling members is provided at a displacement position whereat the rolling members transmit a predetermined transmission torque, and a means is provided for decreasing a wedge angle at a position before the rolling members arrive at the displacement position.
U.S. Pat. No. 5,573,094, which is assigned in common with the present invention and incorporated herein by reference, discloses a combination bearing/freewheel clutch that is provided with an inner race member defining an inner race surface, an outer race member defining an outer race surface concentric with the inner race member, and a raceway between the inner and outer races. The inner and outer race members each have a series of short radially oriented sawtooth inclines in their respective inner and outer race surfaces at right angles to the raceway. A plurality of modified ball bearings, for instance ball bearings have flattened poles, are disposed in the raceway between the inner and outer race members, such that the modified ball bearings serve to prevent relative rotation of the inner and outer race members in one direction, and to transmit a torque between the inner and outer races.
Although the invention of U.S. Pat. No. 5,573,094 represents a significant development in the art of combination bearing/freewheel clutches, there is need for improvement to provide a rolling-element clutch that is stronger, lighter, more reliable, easier to manufacture, and easier to assemble.